Combined extraction and mixed-pressure turbine.



E; 1). DICKINSON. COMBINED EXTRACTION AND MIXED PRESSURE TURBINE.

APPLICATION FILED OGT.24,1914.

Patented Jan-26, 1915.

ZSHEETSSHEET 1.

Inventor; Edgar D. Dickinson His A'ttorrieg.

E D. DICKINSON. COMBINED EXTRACTION AND MIXED PRESSURE TURBINE.

I I APPLICATION FILED 00124, 1914. 1,126,414;, Patented Jan.26, 1915.

2 SHEETS-SHEET 2.

3'3 Fig. 2.

r IF Witnesses: Inventor:

,% Ed 8T D. Dickinsor l,

D '5 by :His fiitorneg.

run erase FATE oration.

D. DICKINSON, ,OF SCHENECTADY, NEVI YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION. OF NEWYORK.

To all whom it may concern Be it known that I, EDGAR D. DicKiNsoN, a subject of the King of Great Britain, residing Schenectady, county of Schenectady, State of New York, have invented ccr teinnew and useful improvements in Com- Extraction and lvlixed-lressure Turbines, ofwhich the following is a specificatioii. y This invention relates to that class of swam turbines wherein a portion of the motive fluid exhausting from a. suitable pressure stage or iegion is utilized in an extrac tion or consumption system for some industrial purpose,such as heating, cooking, drying or the like. lo a pending application of 'minepfiled Oct, '2, 1912, Serial No. 724,267, i have shown a turbine of this sort in which thesteam pressure in thecxtraction or consumption system is kept constant by providing a bypass for conducting the excess steam to thenext lower stage of the turbine, said bypass having a throttle valve controlled not only a pressure responsive device exposed to thepress'u're in the extraction system but also by the speed governor which controls the' higli pressure admission valves of the turbine. The consequence is that the action ofthe pressure responsive device in opening the bypass to reduce thepressure-in the consumption system, which tendsto speed up thetul bine'jby admitting more steam to the sewer stages, is'counteracted by the'closing mov cent of the high pressure valves, rci-ducn {the initiai supply of steam to the turbine, and thus causing it to maintain a constant speed irrespective of the demand of the oonsu i'iptionsyetem.

Theprefsent invention follows the lines of the fol-meione and in construction closely resembles it; But a further provision is made for utilizing in the turbine any excess of steam. in the extract on or consumption system; iIn other Words, the turbine floated on the steam line, and operates auto 'niatically either as an extraction turbine feeding low pressure steam to the consumption system, or as a mixed pressure turbine using the excess low pressure steam from the consumpt' J o? to earry or a; t in the F i i Specification of Letters Patent.

CGEJXBINED EXTEACTIQN AND MIXED-PRESSURE TURBINE.

Patented J an. 26, 1915.

Application filed October 2 1,. 1914. Serial No. 868,410.

I am aware nobody has heretofore attempted to meet this situation.

My invention therefore comprises a. turbine having a bypass between two stagesthereof, controlled by a valve which opens and closes simultaneously with. the high pressure admission valve or-valves under the control of the speed governor, an extraction conduit leading from an intermediate region tal turbine embodying my improvements,

and Fig. 2 is a diagram of the operating mechanism.

The turbine illustrated is of the Curtis type, having three high pressure stages 1, 2, 3 and three low pressure stages 4, 5, and 6; but the invention is not limited to this type of turbine or to the specified number of stages. High pressure steam is admitted to stage 1 through nozzles 7 controlled by valves 8 which are lifted by lovers 9 actuated by cams on a cam shaft 10. A pinion 11 on this shaft meshes with a rack 12 on the piston rod 13 of a hydraulic motor 14, whose regulator or pilot valve is connected to a floating lever 15 connected at one end to the arm 16 of the speed governor 17.- The other end of the floating lever is connected to the piston rod 13 by adiiHow-up link 18. "When the governor Weights move outwardly and push down the pilot valve, the motor lifts the piston rod 13 and closes one or more of the nozzle valves 8.

Between the 3 and 4 is an extra diaphragm 9 containing an annular chamber 20 which communicates by suitable ports with stage 3 and by nozzles with stage 4. [in annular valve 21 controls the ports and can be adjusted hand, so that Said ports on he opened or closed at wil Around this diaphragm is a bypass comprising a chamber 22 opening from the stage 3, a chamber 23 communicating with the chamber 20 in the diaphragm 19, and a passage .l connecting the chambers 22, 23. A conduit leads from the chamber 22 to a heating or other consumption system, and an overilow valve 26 of the butterfly type for example, controls the passage 2- so that any excess of steam not needed in the consumption system cttn be shunted to the lower stages "of the turbine.

The overflow valve is operated by a hydraulic otor 27 whose; piston rod 28 is pivoted to a floating lever 29 connected at one end to the piston rod 13 of the motor 14 and at the other end by a rod 30 to the arm 31 on the spindle of the valve 26. Avspring 32 affords a yielding connection between the lever 29 and the rod 30.

Anarm 33 is rigidly fastened to the pis ton rod 28, and a link 34 connects this arm to a floating lever 35 pivoted to the pilot valve of the motor 27 and alsoyto a link 36 connecjing it to a lever 37 which is fulcrume extending up from the movable abutment ot a pressure responsive device 40. An adjustable weight -11 'is mounted on the lever 37. Steam admitted from the chamber 22 acts upon the under side of the abutment. By a system of levers and links 42. any movement of the stem I'll) is also imparted in the opposite direction to the link 18, lever 15 and the pilot valve of the valve actuating motor l-l.

'lhewmeration is as follows: Assume first, a steady load on the turbine, and let the de mand for steam in the extraction system increase. This will lower the pressure in chamber 22 and the abutment in the pres surea'rsponsive device 39 will fall, allowing the weight ll to lift the pilot valve of the motor 27 which lowers the left hand end 01 lever 29 and more or less closes the bypass throttle valve 26. This reduces the flow of steam to the lower stages of the turbine and builds up the falling pressure in chamber .22 so as to restore the pressure in the extraction system. Meanwhile, the lowering of the stem 39 ot the pressure responsive device has also acted upon the links and levers connecting it with the pilot valve of the motor l t. lifting said valv and causing the motor to pull down the rack 12 and open more of the high p essure admission valves. The increased flow of high pressure steam to the higher stages enables the turbine still to carry the load and also helps in maintaining the pressure in the. extraction system. Conversely, if the demand for extractirm steam lessens, producing a higher pressure in the chamber 32, the bypass valve 36 will open wider and some of the. nozzle valves 9 will close; thus r storing the normal pressure in the extraction system and preventing the turbine from speeding up. In other words,

at 38 and is pivoted to the stem 39- with a constant load on the turbine, the total quantity of steam flowing through the valves 8 and 26 is automatically propor-' tional, irrespective of the variations in the demand of the extraction system.

Secondly, assume a. variable load on the turbine, with a' steady demand for extraction steam. If the load increases, the turbine tends to slow down, and the speed gowernor causes the motor 14 to pull down the rack 12 and open up more high pressure admission valves 8. The increased flow of steam into chamber 22 would tend to raise the pressure in the extraction system,but this is counteracted by the opening of the bypass valve 26 by means of the floating lever 29, actuated by the downwardly moving piston rod 13 and fuleruming on the piston rod of the motor 27. Conversely, a decreaseil'l' "3 load on the turbine will close some of the valves 8 and will also partly close the bypass valve, to maintain in the extraction system a constant supply of steam at constant pressure.

Thirdly, assume a steady load on the turbins, and a conditionin the extraction system under which low pressure steam is present n1 excess of the demand. The excess of this low pressure steam will flow back into the chamber and pass through the bypass to the lower stages of the turbine. 'Ihis will tend to increase the pressure in the chamber 22. and will also increase the speed ofthe turbine. The pressure regulator and the speed governor will therel'one act together to reduce the supply of high pressure steam in order to maintain a steady spdt'd of the turbine, which will now be running as a mixed prcssureniachine. If the supply otlow pressure steam from the extraction rtvstem increases, tllc bypass valve, will open wider and nozzle valves 8 will close; hequ ise incrcaseof pressure in chamber 22 cat s the pressure responsive device 40 to push down the. pilot valves of both motors 14 and 27 thereby causing the former to close some 0% the nozzles 8 and the latter to open the bypass valve wider. A lessened supply of low pressure steam will cause a reverse operation of these valves.

Fourthly, assume a constant supply of low pressure steam from the extraction system and a variable load on the turbine. If the load increases, the speed tends'to fall, and the speed governor causes the piston rod 13 to drop to open more high pressure valves 8. By means of the lever 29, the rod 13 also pulls the bypass valve wider open to let the additional steam exhausting from stage 3 [low to the lower stages. But if, on the other hand, the load decreases, the speed,

governor will close both the bypass and the high pressure valves. It appears, therefore, that the speed governor through its control of the motor Lt operates to close and open as i the valves 8 and 26 simultaneously, while of one motor, and a pressure responsive dethe pressure regulator controls both motors vice controlling both of said regulators inl t and 27, and operates said valves in oppodependently of the speed governor. 45 site directions. With this arrangement, the 3. In combination, a turbine, a conduit machine will maintain a practically constant connected to a region of intermediate prespressure in the extraction system up to the sure of said turbine, a valve controlling the limits of steam supply or demand, neccsadmission of high pressure fluid to said tursitated by the load which the generator is bine, a valve controlling the flow of fiuid 50 carrying. It is apparent that for each load from the region of intermediate pressure to 10 there is a definite amount of steam which lower stages ofthc turbine, a separate momay be extracted Without crippling the turtor for each valve, a speed governor which bine, and conversely, Whenit is operating on controls the high pressure valve motor, low pressure steam only that amount of means whereby said motor acts on both 55 steam which is necessary to carry the load valves to simultaneously open and close the on the generator can be taken into the masame, and a device responsive to the fluid chine. pressure in said intermediate region which In accordance with the provisions of the causes both motors to operate said valves in patent statutes, I have described the prinopposite directions. 6

ciple of operation of my invention, together al.- The combination with a turbine having with the apparatus which I now consider to a region of intermediate pressure, of a conrepresent the best embodiment thereof; but duit connected with said region, valve means I desire to have it understood that the apadmitting high pressure steam to said turparatus shown is only illustrative, and that bme, a motor for actuating said valve means, 6

the invention can be carried out by other and provided with apilot valve, a speed govmeans. ernor connected to said pilot-valve, a bypass What I claim as new and desire to secure valve controlling the flow of steam from the by Letters Patent of the United States, is region of intermediate pressure to lovrer 1. In combination, a turbine, two regustages of the turbine, a second motor, a float 0 lating valve means therefor, a motor for ing lever pivoted to the piston rods of both so moving each of said valve means, a speed motors and also connected to the bypass governor which controls one of said motors valve, a device responsive to the intermediand thereby simultaneously opens or closes ate pressure controlling said second motor, both the valve means, and a pressure reand a system of links and levers connecting 75 sponsivo device controlling both inotors to said pressure device with the pilot valve of simultaneously open one valve means and the first motor.

close the other. In witness whereof, I have hereunto set 1 In cpnibination, it tufrbine, two regumy hand this 23rd day of October, 1914.

atirm va ve means tiere or two motors one di which is capable of nioving both of EDGAR DICKINSON 40 said valve means and the other motor but lVitnesses:

one of them, each motor having a regulator, HELEN Onrom), a speed governor controlling the regulator h/IARGARET E. WooLLEY. 

